communication

[muralidharjk]

what is the difference between ethernet and DH+,RS-232,DH-485?

 

[jvdcande]

What is the difference between English, French and German? What's the difference between telephone and telegraphy? The first use a different set of words to express what has to be said. The latter use different signals to communicate. It's the same with ethernet, DH+, RS-232 and DH-485.

You can find more on RS 232 here.
DH485 and DH+ are both protocols used by Allen-Bradley. These are both based on RS485, of which you can find more info here. DH485 is limited to 19200baud, while DH+ only uses baudrates above this and limited to 57600baud.
More info on ethernet can be found here.

Kind regards,

 

[muralidharjk]

THANKS Jean Pierre Vandecandelaere,
I HAVE ONE MORE QUESTION
WHAT WILL BE THE DATA TRANSFER RATE BETWEEN SCADA(PC) AND PLC?
IS IT DEPENDS ON PROCESSOR SPEED?

THANKS IN ADVANCE
MJK

 

[dchartier]

Hello muralidharjk;
This will depend amongst other things on the processor speed, but also on the RAM memory available, on the %loading of the CPU, on the existence of a separate communictation processor, on the physical limitations of the protocol selected and the network data rate.
Amongst other things.
Regards,
Daniel Chartier

 

[BobB]

If you wish to find out more about industrial networks try here
http://ourworld.cs.com/rahulsebos/
Lots of good info and links.